A rare case of bilateral periprosthetic fracture of medial condyle of tibia after total knee arthroplasty

Abstract

Introduction: Bilateral periprosthetic fractures of medial condyle of tibia after total knee arthroplasty are of rare incidence, as evident from previous literature. The risk factors include morbid obesity, low bone mass or osteopenia, prolonged use of corticosteroids or even trivial trauma leading to stress fractures. Case Report: We reported a case of bilateral periprosthetic fracture tibia after primary total knee arthroplasty in a patient with severe varus knees and morbid obesity. X-Ray [AP view of knee] and orthoscanograms revealed the fracture; SPECT CT showed evidence of aseptic inflammation and component loosening [Type 1B fracture; Felix Classification]. Revision arthroplasty was done with an augmented long-stem implant and the patient was discharged after a normal postoperative phase on the 10th day. Knee movement at 6 months was 0-120 degrees with satisfactory outcome scores on follow-up. Discussion: The incidence of bilateral periprosthetic fractures of tibia after primary knee arthroplasty are of rare occurrence, and often associated with severe varus malalignment and morbid obesity. Obesity leads to excessive joint overloading, and together with varus malalignment may lead to component loosening, requiring revision arthroplasty. Conclusion: Even though bilateral periprosthetic tibial fractures are rare, immediate diagnosis and treatment is necessary, if associated with varus knees and morbid obesity after primary total knee arthroplasty. Reduction of weight is mandatory before primary total knee arthroplasty to improve the functional outcomes and reduce the incidence of revision arthroplasty.